1. Field of the Invention
This invention relates to scaffolds used in general construction and repair of commercial and residential structures and, more particularly, to a collapsible and adjustable scaffold assembly for supporting one or more workers, as well as construction materials and tools at low level heights of between approximately two feet and approximately six feet above the ground, with height adjustments at two-inch increments. The scaffold assembly collapses for storage and easy transport in and out of homes and buildings.
2. Discussion of the Related Art
Scaffold structures of various types are well known and used in many aspects of construction and repair of commercial and residential buildings. The most common type of scaffold structure incorporates the use of steel or aluminum tubular frame sections which interconnect to form an erected assembly of horizontal and vertical bars that function both as a ladder and a means to support planks to form platforms at one or more levels above the ground. Typically this type of scaffold structure is used when it is necessary to perform various tasks at considerable heights which cannot be done safely with the use of a ladder. However, because this type of scaffold structure can be expensive and requires considerable time for assembly and disassembly, it is generally only practical for use on large construction and repair projects which reach considerable heights, generally above twelve feet.
Other scaffold structures include adjustable scaffolds which have been developed to provide for ease of assembly and quick collapse. Examples of these types of structures can be seen in U.S. Pat. Nos. 1,659,113 and 2,257,876. Other, more elaborate scaffold structures have been developed for use in working on the exterior walls of multi-story buildings. An example of this type of structure is seen in U.S. Pat. No. 6,340,070.
More pertinent to the present invention are portable, and easily collapsible scaffold structures which incorporate the use of a sawhorse frame structure as a base. Examples of sawhorse-type structures are seen in U.S. Pat. Nos. 2,376,787; 4,375,245; 4,877,109; and 4,782,917.
Despite the numerous variations in design and structure of scaffold assemblies proposed in the past, there remains a need for a collapsible and adjustable low level scaffold assembly which is easily assembled, collapsed, stored and transported and which provides an unobstructed walkway and a raised, continuous workbench alongside the walkway, for supporting one or more workers, as well as tools and building materials, at adjusted heights ranging between approximately two feet and six feet above the ground.
The present invention is directed to a collapsible and adjustable scaffold unit having a base frame structure and an upper frame structure which removably attaches to the base frame structure. The base frame structure generally resembles a sawhorse and includes pairs of downwardly and outwardly extending leg members at each end. Lower telescoping sections of each leg member extend and lock into position at one-inch increments to provide independent adjustment of the length of each leg member. The bottom ends of the telescoping sections are provided with ground engaging pivoting feet. The independently adjustable leg members and pivoting feet compensate for grade change and uneven terrain.
The upper frame structure of the scaffold unit includes a vertical post which removably attaches to the base and extends upwardly therefrom. A first brace arm is slidably received on the vertical post and is moveable throughout a range of adjusted height positions. An alloy safety pin is used to selectively lock the first brace arm at any of the adjusted height positions. A second brace arm is attachable to the first brace arm and extends upwardly and outwardly from the vertical post, above and opposite to the first brace arm. A staging plank spanning between two or more of the scaffold units is supported on the first brace arm of each unit to provide an unobstructed walkway. Another plank is supported on the second brace arm of each of the spaced-apart scaffold units to provide a continuous workbench above the walkway. In the preferred embodiment, the workbench is supported at a height of approximately three feet above the walkway and is offset along one side of the scaffold assembly so that it is convenient to workers standing on the walkway without interfering with passage along the walkway. The workbench provides a clear, unobstructed surface for placement of tools and building materials and can support a considerable load, thereby allowing workers to continue a task without having to repeatedly climb off and onto the scaffold to replenish materials or exchange tools. Movement of the first brace arm throughout the range of locked positions on the vertical post of each scaffold unit allows the height of the walkway and workbench to be selectively adjusted according to the needs of the user(s). In the preferred embodiment, the walkway is adjustable from a height of approximately two feet above the ground to a height of approximately six feet above the ground, while the workbench is maintained at a height of approximately three feet above the walkway.
With the foregoing in mind, it is a primary object of the present invention to provide a collapsible and adjustable scaffold assembly which is easy to transport, assemble and dissemble and which provides a continuous, unobstructed walkway and a continuous workbench for supporting construction materials and tools in convenient proximity to one or more workers standing on the walkway.
It is a further object of the present invention to provide a collapsible and adjustable scaffold assembly which is easily assembled on uneven terrain to provide a stable uninterrupted walkway and continuous workbench at selectively adjusted heights above the ground.
It is still a further object of the present invention to provide a collapsible and adjustable scaffold assembly which is freestanding and includes independently adjustable legs and swivel feet to compensate for grade change and uneven terrain.
It is still a further object of the present invention to provide a collapsible and adjustable scaffold assembly which includes at least one and preferably two or more scaffold units each having a base frame structure and an upper frame structure, and wherein the scaffold assembly is easily transported, assembled and disassembled to provide a continuous, uninterrupted walkway at adjusted elevated heights ranging between approximately two feet and six feet above the ground.
It is still a further object of the present invention to provide a collapsible and adjustable scaffold assembly which provides low level staging particularly suited for jobs requiring elevation of workers at heights of between approximately two feet and six feet above the ground.
It is still a further object of the present invention to provide an adjustable scaffold assembly which is completely collapsible and easily transported, and which can be stored in an area measuring approximately 24 inches by 24 inches by 44 inches.
These and other objects and advantages of the present invention are more readily apparent with reference to the following detailed description and accompanying drawings.